//
// Created by zhuyijun on 2021/8/16.
//

#include <iostream>
#include <new>

using namespace std;

const int BUF = 512;
const int N = 5;
char buffer[BUF];

int main() {

    double *pd1, *pd2;
    int i;
    cout << "Calling new and placement new:\n";
    pd1 = new double[N];
    pd2 = new(buffer) double[N];
    for (int i = 0; i < N; ++i) {
        pd2[i] = pd1[i] = 1000 + 20.0 * i;
    }
    cout << "Memory addresses:\n" << " heap: " << pd1 << " static: " << (void *) buffer << endl;
    cout << "Memory contents:\n";
    for (int i = 0; i < N; ++i) {
        cout << pd1[i] << " at" << &pd1[i] << "; ";
        cout << pd2[i] << " at" << &pd2[i] << endl;
    }
    cout << "\n Calling new and placement new a second time:\n";
    double *pd3, *pd4;
    pd3 = new double[N];
    pd4 = new(buffer) double[N];
    for (int i = 0; i < N; ++i) {
        pd4[i] = pd3[i] = 1000 + 40.0 * i;
    }
    cout << "Memory contents:\n";
    for (int i = 0; i < N; ++i) {
        cout << pd3[i] << " at" << &pd3[i] << "; ";
        cout << pd4[i] << " at" << &pd4[i] << endl;
    }
    cout << "\n Calling new and placement new a second time:\n";
    delete[]pd1;
    pd1 = new double[N];
    pd2 = new(buffer + N * sizeof(double)) double[N];
    for (int i = 0; i < N; ++i) {
        pd2[i] = pd1[i] = 1000 + 60.0 * i;
    }
    cout << "Memory contents:\n";
    for (int i = 0; i < N; ++i) {
        cout << pd1[i] << " at" << &pd1[i] << "; ";
        cout << pd2[i] << " at" << &pd2[i] << endl;
    }
    delete[]pd1;
    delete[]pd3;
//    delete[]pd2;
//    delete[]pd4;
    return 0;
}

